I run 205/50/15 ZIIs on Kosei K4rs. The 205/50/15 size gives you an overall diameter of 23" so its like having the same height sidewall as 16" wheels but only weigh 30lbs/wheel and give 4% boost to torque. Stock fit sport wheels weight 38lbs/wheel from what previous threads have said.

This has been my first year autocrossing, after 10 events on stock suspension I find that ZIIs are pretty good for grip, but you need to keep them cool with a sprayer and I have no trouble getting them hot. If they get hotter then 120F you start losing grip. If you can keep them in the 100-110F range they seem to be happiest. They make better rain tires over the rivals from what I have heard from the person I know using the rivals. The one time I ran in the rain I only lost 1 second off my afternoon wet times over my dry morning times. Some people were off 4 or 5 seconds.

The rivals from what I have seen are slightly better tires in general, they don't heat up as much and they don't lose grip when hot. They are the best dry tire. Generally rain has not been an issue in Maryland where I am so I would recommend the Rivals. They also have a AA traction rating on Tire Rack the ZIIs only have an A rating.

Unfortunately the Toyo R1Rs don't look like a good option because they have yet to change them from 140 to 200TW. They have until april next year to change them and the 195 toyos have a really good compound over the larger sizes, but will be illegal next year, if you are buying now they will be 140 and not 200.

I will admit I need to work on my smoothness, so some of the temperature rise may be just less then ideal throttle/brake control. The guy running rivals in my region is a better driver and is driving a 2.3l Mazda 3.

I've never driven a sport so I don't know how the nearly 25% reduction in wheel weight does for acceleration.

I will tell you by the time I bought the new wheels/tires/tire pressure monitors and equipment I spent close to $1500 bucks. It was $1100 for wheels and tires including shipping, but If you ever plan on turning off traction control you will need the monitors. Also to switch between sets of tires you need the an ATEQ Quickset tool. Tried disabling it by pulling the fuse, which isn't SCCA legal and it disabled the Power steering as well XD so that doesn't work. Once you have them though it will only be $400-500 to replace the tires.

 

The traction control can be disabled by dissconecting the traction control switch. It puts the system into an error state. That said, you need to drive a short distance or sit for a bit before it errors out.